"The Ruzicka Family" wrote in message ...
I chose the Delta IV family because
it seemed to cover the largest range in payload weights in a single
family of rockets.


While I'm not totally sure about Delta IV Heavy vs. Atlas V Heavy, I do know
that the other Atlas V configurations (401 through 551) cover a better range
than the Delta IV family.

Delta IV is optimized for GTO missions. Atlas V, with
its higher thrust hydrocarbon first stage, has better
LEO-hauling ability than Delta IV - an important detail
when it comes to potential NASA use. Atlas V is also
proving to be commercially competitive while Delta IV
isn't even being offered for commercial launches. This
probably means that Atlas V is going to cost less than
Delta IV - another important detail for NASA to consider.

- Ed Kyle